The group examined 163 patients who had a cough and randomly prescribed them regular codeine or a chocolate-based medicine called ROCOCO.

They found that those using the chocolate-based medication reported a “significant improvement” in their symptoms within two days, compared to those on the regular cough syrup.

Researchers believe the properties of cocoa are stickier and more viscose than standard medicine. They say the chocolate forms a coating in the throat which helps protect the nerve endings that trigger a cough.